JPS6147221B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vapor deposition method suitable for continuously and stably producing metal thin film type magnetic recording media and other functional thin films over a long period of time. A technology that manufactures media suitable for high-density recording by diagonally depositing Co, Co alloy, etc. on a wide polymer molded substrate in an oxygen atmosphere is attracting attention as a new manufacturing technology for magnetic tape. As the evaporation method used for this purpose, it is said that an electron beam heating type using a refractory container is preferable. In order to continuously perform vapor deposition on long objects using this method, the following requirements must be met:
There is a supply of evaporative materials. In this case, focusing on the good controllability of the electron beam, there is a method that irradiates the feed material with the electron beam and the surface of the evaporated molten metal using a single electron beam generator by devising a deflection magnetic field. Naturally, there are two possible methods: 1) and a method in which a separate electron beam generator is provided exclusively for melting and supply. However, there have been no concrete examples of these being implemented so far, so the present inventor conducted experiments on both, and found that the former causes unstable evaporation;
Since the melt supply position heats the evaporation zone and the melting zone by scanning with one electron beam, it is extremely close to the edge of the evaporation zone, resulting in the occurrence of many pinholes or damage to the substrate due to the influence of splash. Inconveniences occur in the manufacturing of magnetic recording media, such as holes being formed in the magnetic recording media.The latter also increases equipment costs, and the vacuum discharge of the electron beam generator dedicated to melting induces the electron beam generator for evaporation. The disadvantage of being easy to use has become clear. The present invention has been made to eliminate the latter drawback, and its gist is to set the acceleration voltage of the electron beam for evaporation to E _V [KV], and to set the acceleration voltage of the electron beam for melt supply to E _M [KV],
The evaporation source is heated and evaporated under conditions that satisfy the relationship E _V -E _M >5 [KV]. Embodiments of the present invention will be specifically described below with reference to the drawings. [Example 1] As shown in the figure, a cylindrical can 1 (diameter 1 m, width
A polyethylene terephthalate film substrate 2 (thickness
10.5 μm), a magnetic layer of 80% Co and 20% Ni was formed to a thickness of 0.1 μm at a minimum incident angle of 45° in an oxygen atmosphere of 2×10 ⁻⁵ Torr. Evaporation source container 3 is
It is made of ZrO ₂ and has an internal volume of 2.5. Wire 4 with a diameter of 1.5 mm made of 80% Co and 20% Ni as evaporation materials
Further, the acceleration voltage E _V of the electron beam for evaporation was set to E _V =30 [KV], and the acceleration voltage E _M of the electron beam 6 for melting was set to E _M =20 [KV]. In the figure, 7 is an adhesion prevention plate for suppressing the influence of splash, 8 is a delivery shaft, 9 is a winding shaft, and 10 is an intermediate roller. The deposition length was 9000 m, and the deposition was performed five times. The table below summarizes the discharge conditions in the above examples.

[Example 2]

Instead of the wire in Example 1, a rod (diameter 32
mm) as the feed material, E _V =40KV, E _M =
The test was carried out at 30KV with the other conditions being the same as in Example 1. The results are shown in the table below.

[Table] On the other hand, when carried out with E _V = 40KV and E _M = 40KV, 90% of the discharges were affected. In many other combinations,
When we summarized the rates of influence, we found that there was a strong correlation with the value of E _V -E _M , and almost no correlation with other conditions. Note that the above is of course based on the basic condition that materials with less splash are used. Now, from the above, if E _V -E _M is 5 KV or more, the proportion of discharge affected by the dissolution side among the discharges on the evaporation side can be suppressed to 10% or less. And preferably, by providing a difference of 10 KV or more, mutual interference can be further suppressed. Here, in order to improve energy efficiency whether for evaporation or melting, conditions are selected that make it easy to focus the beam, and a high acceleration voltage is selected, resulting in On the contrary, when a discharge occurs, the energy of the discharge increases, and from the above, when multiple electron beam generators are used adjacently, mutual interference is likely to occur within the above condition range. considered to be a thing. As described above, according to the present invention, it is possible to perform vapor deposition stably. Note that the present invention is sufficiently effective in, for example, vapor deposition of Si, vapor deposition of other materials in combination with ion plating, and the like.

[Brief explanation of the drawing]

The figure is a perspective view of the main parts of a vapor deposition apparatus used in an example of the present invention. DESCRIPTION OF SYMBOLS 1... Cylindrical can, 2... Substrate, 3... Evaporation source container, 5... Electron beam for evaporation, 6... Electron beam for melting.

Claims (1)

[Claims] 1. A vapor deposition material supplied into a container having a long axis in a direction parallel to the width direction of a moving substrate is heated and melted by irradiation with a melting electron beam, and the melted vapor deposition material is further heated and melted by irradiation with a melting electron beam. When heating and evaporating by irradiation with an evaporating electron beam to form a deposited film on the substrate, the acceleration voltage of the melting electron beam is set to E.
_M [KV] and the accelerating voltage of the electron beam for evaporation is E _V [KV], the vapor deposition method is characterized in that the condition of E _V −E _M >5 [KV] is satisfied.